Bill Badger, the Army veteran who helped hold down the gunman that shot former U.S. Rep Gabby Giffords, died Wednesday of pneumonia at age 78, his wife said.

Badger was also shot in the head at the 2011 constituent event for Giffords, who was the target of gunman Jared Loughner. But Badger managed to tackle Loughner, helping others hold him down and disarm him before police arrived. Loughner is serving seven consecutive life terms in prison.

Giffords, who lives in Tucson, said she was sad to learn of Badger's passing, The Associated Press reported.

"Bill was not only a great man and a proud Army veteran, he was a hero," she said in a statement. "I believe that Bill helped save lives that morning. And I will always be grateful to him for his selfless, brave actions."

Sallie Badger said it came as no surprise that her husband had risked his life to help others. The retired Army colonel had spent his entire life doing just that, she said.

"Bill was a hero to many, many people long before he became a hero on Jan. 8. He was very influential in many, many young lives in many ways," Sallie Badger said.

She said Badger was highly involved in the life of their 25-year-old son, Christian Badger. Badger also guided young men into the military and other careers, she said.

Bill Badger hailed from South Dakota. He joined the National Guard as a high school junior and went on to have a long, distinguished career as an Army pilot for 37 years.

The couple moved to Arizona in 1985 when Bill Badger established the Western Army Aviation Training Site in Marana, just outside of Tucson.

Badger was not permanently injured from the bullet that grazed the back of his head, but he showed signs of post-traumatic stress disorder, his wife said.

The couple embarked on a three-year journey across the country to push for stricter gun laws.

"We wanted desperately to have background checks on every gun that was sold," Sallie Badger said. "And Bill just made that his mission."